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Yuan X, Jiang YD, Wang GY, Yu H, Zhou WW, Liu S, Yang MF, Cheng J, Gurr GM, Way MO, Zhu ZR. Odorant-Binding Proteins and Chemosensory Proteins from an Invasive Pest Lissorhoptrus oryzophilus (Coleoptera: Curculionidae). ENVIRONMENTAL ENTOMOLOGY 2016; 45:1276-1286. [PMID: 27569597 DOI: 10.1093/ee/nvw111] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 08/01/2016] [Indexed: 06/06/2023]
Abstract
The rice water weevil, Lissorhoptrus oryzophilus Kuschel (Coleoptera: Curculionidae), is a serious pest species both in its original distribution region of northern America and its invaded regions of eastern Asia and southern Europe. The odorant-binding proteins (OBPs) and the chemosensory proteins (CSPs) play important roles in host and mate locating, thus might play a significant role in the success of the species as an invader, which has not been characterized yet. We identified 10 OBPs and 5 CSPs in L. oryzophilus and investigated the expression profiles of these genes in various tissues by quantitative real-time PCR. Five classic OBPs were predominantly expressed in the antennae. CSPs were expressed ubiquitously with particularly high transcript levels in antennae, legs, and wings. Three antenna-specific OBPs (LoOBP1, 8, 11) were up-regulated following 1-3 d of food deprivation and down-regulated afterward. These findings suggest most classic OBPs are likely involved in chemoreception whereas CSPs as well as the minus-C OBPs may have broader physiological functions, which in turn may help to understand the molecular aspects of chemical communication in this invasive insect.
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Affiliation(s)
- Xin Yuan
- State Key Laboratory of Rice Biology and Key Laboratory of Agricultural Entomology, Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, Hangzhou, China (; ; ; ; ; ; ; ; )
| | - Yan-Dong Jiang
- State Key Laboratory of Rice Biology and Key Laboratory of Agricultural Entomology, Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, Hangzhou, China (; ; ; ; ; ; ; ; )
| | - Gui-Yao Wang
- State Key Laboratory of Rice Biology and Key Laboratory of Agricultural Entomology, Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, Hangzhou, China (; ; ; ; ; ; ; ; )
| | - Hang Yu
- State Key Laboratory of Rice Biology and Key Laboratory of Agricultural Entomology, Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, Hangzhou, China (; ; ; ; ; ; ; ; )
| | - Wen-Wu Zhou
- State Key Laboratory of Rice Biology and Key Laboratory of Agricultural Entomology, Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, Hangzhou, China (; ; ; ; ; ; ; ; )
| | - Su Liu
- State Key Laboratory of Rice Biology and Key Laboratory of Agricultural Entomology, Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, Hangzhou, China (; ; ; ; ; ; ; ; )
| | - Mao-Fa Yang
- Institute of Entomology, Guizhou University, Guiyang, China
| | - Jiaan Cheng
- State Key Laboratory of Rice Biology and Key Laboratory of Agricultural Entomology, Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, Hangzhou, China (; ; ; ; ; ; ; ; )
| | - Geoff M Gurr
- State Key Laboratory of Rice Biology and Key Laboratory of Agricultural Entomology, Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, Hangzhou, China (; ; ; ; ; ; ; ; ) Graham Centre for Agricultural Innovation, Charles Sturt University, Orange, NSW, Australia
| | - Michael O Way
- Texas A&M AgriLife Research and Extension Center, Beaumont, TX
| | - Zeng-Rong Zhu
- State Key Laboratory of Rice Biology and Key Laboratory of Agricultural Entomology, Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, Hangzhou, China (; ; ; ; ; ; ; ; )
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Koenecke N, Johnston J, Gaertner B, Natarajan M, Zeitlinger J. Genome-wide identification of Drosophila dorso-ventral enhancers by differential histone acetylation analysis. Genome Biol 2016; 17:196. [PMID: 27678375 PMCID: PMC5037609 DOI: 10.1186/s13059-016-1057-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Accepted: 09/05/2016] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Drosophila dorso-ventral (DV) patterning is one of the best-understood regulatory networks to date, and illustrates the fundamental role of enhancers in controlling patterning, cell fate specification, and morphogenesis during development. Histone acetylation such as H3K27ac is an excellent marker for active enhancers, but it is challenging to obtain precise locations for enhancers as the highest levels of this modification flank the enhancer regions. How to best identify tissue-specific enhancers in a developmental system de novo with a minimal set of data is still unclear. RESULTS Using DV patterning as a test system, we develop a simple and effective method to identify tissue-specific enhancers de novo. We sample a broad set of candidate enhancer regions using data on CREB-binding protein co-factor binding or ATAC-seq chromatin accessibility, and then identify those regions with significant differences in histone acetylation between tissues. This method identifies hundreds of novel DV enhancers and outperforms ChIP-seq data of relevant transcription factors when benchmarked with mRNA expression data and transgenic reporter assays. These DV enhancers allow the de novo discovery of the relevant transcription factor motifs involved in DV patterning and contain additional motifs that are evolutionarily conserved and for which the corresponding transcription factors are expressed in a DV-biased fashion. Finally, we identify novel target genes of the regulatory network, implicating morphogenesis genes as early targets of DV patterning. CONCLUSIONS Taken together, our approach has expanded our knowledge of the DV patterning network even further and is a general method to identify enhancers in any developmental system, including mammalian development.
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Affiliation(s)
- Nina Koenecke
- Stowers Institute for Medical Research, Kansas City, MO, 64110, USA
| | - Jeff Johnston
- Stowers Institute for Medical Research, Kansas City, MO, 64110, USA
| | - Bjoern Gaertner
- Stowers Institute for Medical Research, Kansas City, MO, 64110, USA.,Present address: Department of Pediatrics, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Malini Natarajan
- Stowers Institute for Medical Research, Kansas City, MO, 64110, USA
| | - Julia Zeitlinger
- Stowers Institute for Medical Research, Kansas City, MO, 64110, USA. .,Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS, 66160, USA.
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Urbach R, Jussen D, Technau GM. Gene expression profiles uncover individual identities of gnathal neuroblasts and serial homologies in the embryonic CNS of Drosophila. Development 2016; 143:1290-301. [PMID: 27095493 PMCID: PMC4852520 DOI: 10.1242/dev.133546] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 02/22/2016] [Indexed: 01/25/2023]
Abstract
The numbers and types of progeny cells generated by neural stem cells in the developing CNS are adapted to its region-specific functional requirements. In Drosophila, segmental units of the CNS develop from well-defined patterns of neuroblasts. Here we constructed comprehensive neuroblast maps for the three gnathal head segments. Based on the spatiotemporal pattern of neuroblast formation and the expression profiles of 46 marker genes (41 transcription factors), each neuroblast can be uniquely identified. Compared with the thoracic ground state, neuroblast numbers are progressively reduced in labial, maxillary and mandibular segments due to smaller sizes of neuroectodermal anlagen and, partially, to suppression of neuroblast formation and induction of programmed cell death by the Hox gene Deformed. Neuroblast patterns are further influenced by segmental modifications in dorsoventral and proneural gene expression. With the previously published neuroblast maps and those presented here for the gnathal region, all neuroectodermal neuroblasts building the CNS of the fly (ventral nerve cord and brain, except optic lobes) are now individually identified (in total 2×567 neuroblasts). This allows, for the first time, a comparison of the characteristics of segmental populations of stem cells and to screen for serially homologous neuroblasts throughout the CNS. We show that approximately half of the deutocerebral and all of the tritocerebral (posterior brain) and gnathal neuroblasts, but none of the protocerebral (anterior brain) neuroblasts, display serial homology to neuroblasts in thoracic/abdominal neuromeres. Modifications in the molecular signature of serially homologous neuroblasts are likely to determine the segment-specific characteristics of their lineages. Highlighted article: Characterisation of the neural stem cells in the gnathal head region completes the mapping of all individual neuroblasts that generate the Drosophila CNS.
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Affiliation(s)
- Rolf Urbach
- Institute of Genetics, University of Mainz, Mainz D-55099, Germany
| | - David Jussen
- Institute of Genetics, University of Mainz, Mainz D-55099, Germany
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54
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Pers D, Buchta T, Özüak O, Wolff S, Pietsch JM, Memon MB, Roth S, Lynch JA. Global analysis of dorsoventral patterning in the wasp Nasonia reveals extensive incorporation of novelty in a regulatory network. BMC Biol 2016; 14:63. [PMID: 27480122 PMCID: PMC4968023 DOI: 10.1186/s12915-016-0285-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 07/18/2016] [Indexed: 01/23/2023] Open
Abstract
Background Gene regulatory networks (GRNs) underlie developmental patterning and morphogenetic processes, and changes in the interactions within the underlying GRNs are a major driver of evolutionary processes. In order to make meaningful comparisons that can provide significant insights into the evolution of regulatory networks, homologous networks from multiple taxa must be deeply characterized. One of the most thoroughly characterized GRNs is the dorsoventral (DV) patterning system of the Drosophila melanogaster embryo. We have developed the wasp Nasonia as a comparative DV patterning model because it has shown the convergent evolution of a mode of early embryonic patterning very similar to that of the fly, and it is of interest to know whether the similarity at the gross level also extends to the molecular level. Results We used RNAi to dorsalize and ventralize Nasonia embryos, RNAseq to quantify transcriptome-wide expression levels, and differential expression analysis to identify genes whose expression levels change in either RNAi case. This led to the identification of >100 genes differentially expressed and regulated along the DV axis. Only a handful of these genes are shared DV components in both fly and wasp. Many of those unique to Nasonia are cytoskeletal and adhesion molecules, which may be related to the divergent cell and tissue behavior observed at gastrulation. In addition, many transcription factors and signaling components are only DV regulated in Nasonia, likely reflecting the divergent upstream patterning mechanisms involved in producing the conserved pattern of cell fates observed at gastrulation. Finally, several genes that lack Drosophila orthologs show robust and distinct expression patterns. These include genes with vertebrate homologs that have been lost in the fly lineage, genes that are found only among Hymenoptera, and several genes that entered the Nasonia genome through lateral transfer from endosymbiotic bacteria. Conclusions Altogether, our results provide insights into how GRNs respond to new functional demands and how they can incorporate novel components. Electronic supplementary material The online version of this article (doi:10.1186/s12915-016-0285-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Daniel Pers
- Department of Biological Sciences, University of Illinois at Chicago, MBRB 4020, 900 S. Ashland Avenue, Chicago, IL, 60402, USA
| | - Thomas Buchta
- Institute for Developmental Biology, University at Cologne, Cologne, Germany
| | - Orhan Özüak
- Institute for Developmental Biology, University at Cologne, Cologne, Germany
| | - Selma Wolff
- Institute for Developmental Biology, University at Cologne, Cologne, Germany
| | - Jessica M Pietsch
- Institute for Developmental Biology, University at Cologne, Cologne, Germany
| | - Mohammad Bilal Memon
- Department of Biological Sciences, University of Illinois at Chicago, MBRB 4020, 900 S. Ashland Avenue, Chicago, IL, 60402, USA
| | - Siegfried Roth
- Institute for Developmental Biology, University at Cologne, Cologne, Germany
| | - Jeremy A Lynch
- Department of Biological Sciences, University of Illinois at Chicago, MBRB 4020, 900 S. Ashland Avenue, Chicago, IL, 60402, USA.
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Esposito E, Lim B, Guessous G, Falahati H, Levine M. Mitosis-associated repression in development. Genes Dev 2016; 30:1503-8. [PMID: 27401553 PMCID: PMC4949323 DOI: 10.1101/gad.281188.116] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Accepted: 06/13/2016] [Indexed: 11/25/2022]
Abstract
Transcriptional repression is a pervasive feature of animal development. Here, we employ live-imaging methods to visualize the Snail repressor, which establishes the boundary between the presumptive mesoderm and neurogenic ectoderm of early Drosophila embryos. Snail target enhancers were attached to an MS2 reporter gene, permitting detection of nascent transcripts in living embryos. The transgenes exhibit initially broad patterns of transcription but are refined by repression in the mesoderm following mitosis. These observations reveal a correlation between mitotic silencing and Snail repression. We propose that mitosis and other inherent discontinuities in transcription boost the activities of sequence-specific repressors, such as Snail.
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Affiliation(s)
- Emilia Esposito
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544, USA; Department of Molecular and Cell Biology, Division of Genetics, Genomics, and Development, University of California at Berkeley, Berkeley, California 94720, USA
| | - Bomyi Lim
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544, USA
| | - Ghita Guessous
- Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - Hanieh Falahati
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544, USA
| | - Michael Levine
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544, USA; Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA
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NF-YB Regulates Spermatogonial Stem Cell Self-Renewal and Proliferation in the Planarian Schmidtea mediterranea. PLoS Genet 2016; 12:e1006109. [PMID: 27304889 PMCID: PMC4909293 DOI: 10.1371/journal.pgen.1006109] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 05/16/2016] [Indexed: 12/21/2022] Open
Abstract
Gametes are the source and carrier of genetic information, essential for the propagation of all sexually reproducing organisms. Male gametes are derived from a progenitor stem cell population called spermatogonial stem cells (SSCs). SSCs give rise to male gametes through the coordination of two essential processes: self-renewal to produce more SSCs, and differentiation to produce mature sperm. Disruption of this equilibrium can lead to excessive proliferation of SSCs, causing tumorigenesis, or can result in aberrant differentiation, leading to infertility. Little is known about how SSCs achieve the fine balance between self-renewal and differentiation, which is necessary for their remarkable output and developmental potential. To understand the mechanisms of SSC maintenance, we examine the planarian homolog of Nuclear Factor Y-B (NF-YB), which is required for the maintenance of early planarian male germ cells. Here, we demonstrate that NF-YB plays a role in the self-renewal and proliferation of planarian SSCs, but not in their specification or differentiation. Furthermore, we characterize members of the NF-Y complex in Schistosoma mansoni, a parasitic flatworm related to the free-living planarian. We find that the function of NF-YB in regulating male germ cell proliferation is conserved in schistosomes. This finding is especially significant because fecundity is the cause of pathogenesis of S. mansoni. Our findings can help elucidate the complex relationship between self-renewal and differentiation of SSCs, and may also have implications for understanding and controlling schistosomiasis.
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57
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Sandler JE, Stathopoulos A. Stepwise Progression of Embryonic Patterning. Trends Genet 2016; 32:432-443. [PMID: 27230753 DOI: 10.1016/j.tig.2016.04.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 04/20/2016] [Accepted: 04/21/2016] [Indexed: 01/23/2023]
Abstract
It is long established that the graded distribution of Dorsal transcription factor influences spatial domains of gene expression along the dorsoventral (DV) axis of Drosophila melanogaster embryos. However, the more recent realization that Dorsal levels also change with time raises the question of whether these dynamics are instructive. An overview of DV axis patterning is provided, focusing on new insights identified through quantitative analysis of temporal changes in Dorsal target gene expression from one nuclear cycle to the next ('steps'). Possible roles for the stepwise progression of this patterning program are discussed including (i) tight temporal regulation of signaling pathway activation, (ii) control of gene expression cohorts, and (iii) ensuring the irreversibility of the patterning and cell fate specification process.
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Affiliation(s)
- Jeremy E Sandler
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Angelike Stathopoulos
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
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58
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The Friend of GATA Transcriptional Co-Regulator, U-Shaped, Is a Downstream Antagonist of Dorsal-Driven Prohemocyte Differentiation in Drosophila. PLoS One 2016; 11:e0155372. [PMID: 27163255 PMCID: PMC4862636 DOI: 10.1371/journal.pone.0155372] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 04/27/2016] [Indexed: 12/11/2022] Open
Abstract
Recent studies suggest that mammalian hematopoietic stem and progenitor cells (HSPCs) respond directly to infection and inflammatory signaling. These signaling pathways also regulate HSPCs during steady-state conditions (absence of infection), and dysregulation may lead to cancer or age-related loss of progenitor repopulation capacity. Toll-like receptors (TLRs) are a major class of pathogen recognition receptors, and are expressed on the surface of immune effector cells and HSPCs. TLR/NF-κB activation promotes HSPCs differentiation; however, the mechanisms by which this signaling pathway alters the intrinsic transcriptional landscape are not well understood. Although Drosophila prohemocytes are the functional equivalent of mammalian HSPCs, a prohemocyte-specific function for Toll signaling has not been reported. Using Drosophila transgenics, we identified prohemocyte-specific roles for Toll pathway members, Dorsal and Cactus. We showed that Dorsal is required to limit the size of the progenitor pool. Additionally, we showed that activation of Toll signaling in prohemocytes drives differentiation in a manner that is analogous to TLR/NF-κB-driven HSPC differentiation. This was accomplished by showing that over-expression of Dorsal, or knockdown of Cactus, promotes differentiation. We also investigated whether Dorsal and Cactus control prohemocyte differentiation by regulating a key intrinsic prohemocyte factor, U-shaped (Ush), which is known to promote multipotency and block differentiation. We showed that Dorsal repressed Ush expression levels to promote differentiation, whereas Cactus maintained Ush levels to block differentiation. Additionally, we showed that another Toll antagonist, Lesswright, also maintained the level of Ush to block differentiation and promote proliferative quiescence. Collectively, these results identify a novel role for Ush as a downstream target of Toll signaling.
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59
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Levario TJ, Lim B, Shvartsman SY, Lu H. Microfluidics for High-Throughput Quantitative Studies of Early Development. Annu Rev Biomed Eng 2016; 18:285-309. [PMID: 26928208 DOI: 10.1146/annurev-bioeng-100515-013926] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Developmental biology has traditionally relied on qualitative analyses; recently, however, as in other fields of biology, researchers have become increasingly interested in acquiring quantitative knowledge about embryogenesis. Advances in fluorescence microscopy are enabling high-content imaging in live specimens. At the same time, microfluidics and automation technologies are increasing experimental throughput for studies of multicellular models of development. Furthermore, computer vision methods for processing and analyzing bioimage data are now leading the way toward quantitative biology. Here, we review advances in the areas of fluorescence microscopy, microfluidics, and data analysis that are instrumental to performing high-content, high-throughput studies in biology and specifically in development. We discuss a case study of how these techniques have allowed quantitative analysis and modeling of pattern formation in the Drosophila embryo.
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Affiliation(s)
- Thomas J Levario
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332;
| | - Bomyi Lim
- Department of Chemical and Biological Engineering and Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544;
| | - Stanislav Y Shvartsman
- Department of Chemical and Biological Engineering and Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544;
| | - Hang Lu
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332;
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Cavalieri V, Spinelli G. Ectopic hbox12 Expression Evoked by Histone Deacetylase Inhibition Disrupts Axial Specification of the Sea Urchin Embryo. PLoS One 2015; 10:e0143860. [PMID: 26618749 PMCID: PMC4664418 DOI: 10.1371/journal.pone.0143860] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 11/09/2015] [Indexed: 12/26/2022] Open
Abstract
Dorsal/ventral patterning of the sea urchin embryo depends upon the establishment of a Nodal-expressing ventral organizer. Recently, we showed that spatial positioning of this organizer relies on the dorsal-specific transcription of the Hbox12 repressor. Building on these findings, we determined the influence of the epigenetic milieu on the expression of hbox12 and nodal genes. We find that Trichostatin-A, a potent and selective histone-deacetylases inhibitor, induces histone hyperacetylation in hbox12 chromatin, evoking broad ectopic expression of the gene. Transcription of nodal concomitantly drops, prejudicing dorsal/ventral polarity of the resulting larvae. Remarkably, impairing hbox12 function, either in a spatially-restricted sector or in the whole embryo, specifically rescues nodal transcription in Trichostatin-A-treated larvae. Beyond strengthen the notion that nodal expression is not allowed in the presence of functional Hbox12 in the same cells, these results highlight a critical role of histone deacetylases in regulating the spatial expression of hbox12.
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Affiliation(s)
- Vincenzo Cavalieri
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Italy
- Mediterranean Center for Human Health Advanced Biotechnologies (CHAB), University of Palermo, Italy
- * E-mail: (VC); (GS)
| | - Giovanni Spinelli
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Italy
- * E-mail: (VC); (GS)
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Zehavi Y, Sloutskin A, Kuznetsov O, Juven-Gershon T. The core promoter composition establishes a new dimension in developmental gene networks. Nucleus 2015; 5:298-303. [PMID: 25482118 DOI: 10.4161/nucl.29838] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Developmental processes are highly dependent on transcriptional regulation by RNA polymerase II, which initiates transcription at the core promoter. The dorsal-ventral gene regulatory network (GRN) includes multiple genes that are activated by different nuclear concentrations of the Dorsal transcription factor along the dorsal-ventral axis. Downstream core promoter element (DPE)-containing genes are conserved and highly prevalent among Dorsal target genes. Moreover, the DPE motif is functional in multiple Dorsal target genes, as mutation of the DPE results in the loss of transcriptional activity. Furthermore, analysis of hybrid enhancer-promoter constructs reveals that the core promoter composition plays a pivotal role in the transcriptional output. Importantly, we provide in vivo evidence that expression driven by the homeotic Antennapedia P2 promoter during Drosophila embryogenesis is dependent on the DPE. Taken together, we propose that transcriptional regulation results from the interplay between enhancers and core promoter composition, thus establishing a novel dimension in developmental GRNs.
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Affiliation(s)
- Yonathan Zehavi
- a The Mina and Everard Goodman Faculty of Life Sciences; Bar-Ilan University; Ramat Gan, Israel
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62
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Hojo MK, Ishii K, Sakura M, Yamaguchi K, Shigenobu S, Ozaki M. Antennal RNA-sequencing analysis reveals evolutionary aspects of chemosensory proteins in the carpenter ant, Camponotus japonicus. Sci Rep 2015; 5:13541. [PMID: 26310137 PMCID: PMC4550911 DOI: 10.1038/srep13541] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 07/30/2015] [Indexed: 11/17/2022] Open
Abstract
Chemical communication is essential for the coordination of complex organisation in ant societies. Recent comparative genomic approaches have revealed that chemosensory genes are diversified in ant lineages, and suggest that this diversification is crucial for social organisation. However, how such diversified genes shape the peripheral chemosensory systems remains unknown. In this study, we annotated and analysed the gene expression profiles of chemosensory proteins (CSPs), which transport lipophilic compounds toward chemosensory receptors in the carpenter ant, Camponotus japonicus. Transcriptome analysis revealed 12 CSP genes and phylogenetic analysis showed that 3 of these are lineage-specifically expanded in the clade of ants. RNA sequencing and real-time quantitative polymerase chain reaction revealed that, among the ant specific CSP genes, two of them (CjapCSP12 and CjapCSP13) were specifically expressed in the chemosensory organs and differentially expressed amongst ant castes. Furthermore, CjapCSP12 and CjapCSP13 had a ratio of divergence at non-synonymous and synonymous sites (dN/dS) greater than 1, and they were co-expressed with CjapCSP1, which is known to bind cuticular hydrocarbons. Our results suggested that CjapCSP12 and CjapCSP13 were functionally differentiated for ant-specific chemosensory events, and that CjapCSP1, CjapCSP12, and CjapCSP13 work cooperatively in the antennal chemosensilla of worker ants.
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Affiliation(s)
- Masaru K Hojo
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan
| | - Kenichi Ishii
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Midori Sakura
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan
| | - Katsushi Yamaguchi
- NIBB Core Research Facilities, National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, Japan
| | - Shuji Shigenobu
- NIBB Core Research Facilities, National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, Japan.,Department of Basic Biology, School of Life Science, Graduate University for Advanced Studies, Okazaki, Japan
| | - Mamiko Ozaki
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan
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63
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Pocha SM, Montell DJ. Cellular and molecular mechanisms of single and collective cell migrations in Drosophila: themes and variations. Annu Rev Genet 2015; 48:295-318. [PMID: 25421599 DOI: 10.1146/annurev-genet-120213-092218] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The process of cell migration is essential throughout life, driving embryonic morphogenesis and ensuring homeostasis in adults. Defects in cell migration are a major cause of human disease, with excessive migration causing autoimmune diseases and cancer metastasis, whereas reduced capacity for migration leads to birth defects and immunodeficiencies. Myriad studies in vitro have established a consensus view that cell migrations require cell polarization, Rho GTPase-mediated cytoskeletal rearrangements, and myosin-mediated contractility. However, in vivo studies later revealed a more complex picture, including the discovery that cells migrate not only as single units but also as clusters, strands, and sheets. In particular, the role of E-Cadherin in cell motility appears to be more complex than previously appreciated. Here, we discuss recent advances achieved by combining the plethora of genetic tools available to the Drosophila geneticist with live imaging and biophysical techniques. Finally, we discuss the emerging themes such studies have revealed and ponder the puzzles that remain to be solved.
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Affiliation(s)
- Shirin M Pocha
- Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California; 93106-9625; ,
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64
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Dobi KC, Schulman VK, Baylies MK. Specification of the somatic musculature in Drosophila. WILEY INTERDISCIPLINARY REVIEWS. DEVELOPMENTAL BIOLOGY 2015; 4:357-75. [PMID: 25728002 PMCID: PMC4456285 DOI: 10.1002/wdev.182] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Revised: 01/16/2015] [Accepted: 02/04/2015] [Indexed: 11/09/2022]
Abstract
The somatic muscle system formed during Drosophila embryogenesis is required for larvae to hatch, feed, and crawl. This system is replaced in the pupa by a new adult muscle set, responsible for activities such as feeding, walking, and flight. Both the larval and adult muscle systems are comprised of distinct muscle fibers to serve these specific motor functions. In this way, the Drosophila musculature is a valuable model for patterning within a single tissue: while all muscle cells share properties such as the contractile apparatus, properties such as size, position, and number of nuclei are unique for a particular muscle. In the embryo, diversification of muscle fibers relies first on signaling cascades that pattern the mesoderm. Subsequently, the combinatorial expression of specific transcription factors leads muscle fibers to adopt particular sizes, shapes, and orientations. Adult muscle precursors (AMPs), set aside during embryonic development, proliferate during the larval phases and seed the formation of the abdominal, leg, and flight muscles in the adult fly. Adult muscle fibers may either be formed de novo from the fusion of the AMPs, or are created by the binding of AMPs to an existing larval muscle. While less is known about adult muscle specification compared to the larva, expression of specific transcription factors is also important for its diversification. Increasingly, the mechanisms required for the diversification of fly muscle have found parallels in vertebrate systems and mark Drosophila as a robust model system to examine questions about how diverse cell types are generated within an organism.
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Affiliation(s)
- Krista C. Dobi
- Program in Developmental Biology, Sloan Kettering Institute, New York, NY, USA
| | - Victoria K. Schulman
- Program in Developmental Biology, Sloan Kettering Institute, New York, NY, USA
- Cell and Developmental Biology, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, NY, USA
| | - Mary K. Baylies
- Program in Developmental Biology, Sloan Kettering Institute, New York, NY, USA
- Cell and Developmental Biology, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, NY, USA
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65
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Li ZQ, Zhang S, Luo JY, Zhu J, Cui JJ, Dong SL. Expression Analysis and Binding Assays in the Chemosensory Protein Gene Family Indicate Multiple Roles in Helicoverpa armigera. J Chem Ecol 2015; 41:473-85. [PMID: 25893790 DOI: 10.1007/s10886-015-0574-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Revised: 02/04/2015] [Accepted: 03/06/2015] [Indexed: 11/29/2022]
Abstract
Chemosensory proteins (CSPs) have been proposed to capture and transport hydrophobic chemicals to receptors on sensory neurons. We identified and cloned 24 CSP genes to better understand the physiological function of CSPs in Helicoverpa armigera. Quantitative real-time polymerase chain reaction assays indicate that CSP genes are ubiquitously expressed in adult H. armigera tissues. Broad expression patterns in adult tissues suggest that CSPs are involved in a diverse range of cellular processes, including chemosensation as well as other functions not related to chemosensation. The H. armigera CSPs that were highly transcribed in sensory organs or pheromone glands (HarmCSPs 6, 9, 18, 19), were recombinantly expressed in bacteria to explore their function. Fluorescent competitive binding assays were used to measure the binding affinities of these CSPs against 85 plant volatiles and 4 pheromone components. HarmCSP6 displays high binding affinity for pheromone components, whereas the other three proteins do not show affinities for any of the compounds tested. HarmCSP6 is expressed in numerous cells located in or close to long sensilla trichodea on the antennae of both males and females. These results suggest that HarmCSP6 may be involved in transporting female sex pheromones in H. armigera.
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Affiliation(s)
- Zhao-Qun Li
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, China
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66
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Zhang ZK, Lei ZR. Identification, expression profiling and fluorescence-based binding assays of a chemosensory protein gene from the Western flower thrips, Frankliniella occidentalis. PLoS One 2015; 10:e0117726. [PMID: 25635391 PMCID: PMC4311994 DOI: 10.1371/journal.pone.0117726] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 12/31/2014] [Indexed: 11/18/2022] Open
Abstract
Using RT-PCR and RACE-PCR strategies, we cloned and identified a new chemosensory protein (FoccCSP) from the Western flower thrips, Frankliniella occidentalis, a species for which no chemosensory protein (CSP) has yet been identified. The FoccCSP gene contains a 387 bp open-reading frame encoding a putative protein of 128 amino acids with a molecular weight of 14.51 kDa and an isoelectric point of 5.41. The deduced amino acid sequence contains a putative signal peptide of 19 amino acid residues at the N-terminus, as well as the typical four-cysteine signature found in other insect CSPs. As FoccCSP is from a different order of insect than other known CSPs, the GenBank FoccCSP homolog showed only 31-50% sequence identity with them. A neighbor-joining tree was constructed and revealed that FoccCSP is in a group with CSPs from Homopteran insects (e.g., AgosCSP4, AgosCSP10, ApisCSP, and NlugCSP9), suggesting that these genes likely developed from a common ancestral gene. The FoccCSP gene expression profile of different tissues and development stages was measured by quantitative real-time PCR. The results of this analysis revealed this gene is predominantly expressed in the antennae and also highly expressed in the first instar nymph, suggesting a function for FoccCSP in olfactory reception and in particular life activities during the first instar nymph stage. We expressed recombinant FoccCSP protein in a prokaryotic expression system and purified FoccCSP protein by affinity chromatography using a Ni-NTA-Sepharose column. Using N-phenyl-1-naphthylamine (1-NPN) as a fluorescent probe in fluorescence-based competitive binding assay, we determined the binding affinities of 19 volatile substances for FoccCSP protein. This analysis revealed that anisic aldehyde, geraniol and methyl salicylate have high binding affinities for FoccCSP, with KD values of 10.50, 15.35 and 35.24 μM, respectively. Thus, our study indicates that FoccCSP may play an important role in regulating the development of the first instar nymph and mediate F. occidentalis host recognition.
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Affiliation(s)
- Zhi-Ke Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- Institute of Plant Protection, Ningxia Academy of Agriculture and Forestry Sciences, Yinchuan, China
| | - Zhong-Ren Lei
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
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Li S, Wang S, Wang X, Li X, Zi J, Ge S, Cheng Z, Zhou T, Ji Y, Deng J, Wong SM, Zhou Y. Rice stripe virus affects the viability of its vector offspring by changing developmental gene expression in embryos. Sci Rep 2015; 5:7883. [PMID: 25601039 PMCID: PMC4298728 DOI: 10.1038/srep07883] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2014] [Accepted: 12/16/2014] [Indexed: 11/13/2022] Open
Abstract
Plant viruses may affect the viability and development process of their herbivore vectors. Small brown planthopper (SBPH) is main vector of Rice stripe virus (RSV), which causes serious rice stripe disease. Here, we reported the effects of RSV on SBPH offspring by crossing experiments between viruliferous and non-viruliferous strains. The life parameters of offspring from different cross combinations were compared. The hatchability of F1 progeny from viruliferous parents decreased significantly, and viruliferous rate was completely controlled by viruliferous maternal parent. To better elucidate the underlying biological mechanisms, the morphology of eggs, viral propagation and distribution in the eggs and expression profile of embryonic development genes were investigated. The results indicated that RSV replicated and accumulated in SBPH eggs resulting in developmental stunt or delay of partial eggs; in addition, RSV was only able to infect ovum but not sperm. According to the expression profile, expression of 13 developmental genes was regulated in the eggs from viruliferous parents, in which two important regulatory genes (Ls-Dorsal and Ls-CPO) were most significantly down-regulated. In general, RSV exerts an adverse effect on SBPH, which is unfavourable for the expansion of viruliferous populations. The viewpoint is also supported by systematic monitoring of SBPH viruliferous rate.
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Affiliation(s)
- Shuo Li
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences; Jiangsu Technical Service Center of Diagnosis and Detection for Plant Virus Diseases, Nanjing 210014, People's Republic of China
| | - Shijuan Wang
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences; Jiangsu Technical Service Center of Diagnosis and Detection for Plant Virus Diseases, Nanjing 210014, People's Republic of China
| | - Xi Wang
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences; Jiangsu Technical Service Center of Diagnosis and Detection for Plant Virus Diseases, Nanjing 210014, People's Republic of China
| | - Xiaoli Li
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences; Jiangsu Technical Service Center of Diagnosis and Detection for Plant Virus Diseases, Nanjing 210014, People's Republic of China
| | - Jinyan Zi
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences; Jiangsu Technical Service Center of Diagnosis and Detection for Plant Virus Diseases, Nanjing 210014, People's Republic of China
| | - Shangshu Ge
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences; Jiangsu Technical Service Center of Diagnosis and Detection for Plant Virus Diseases, Nanjing 210014, People's Republic of China
| | - Zhaobang Cheng
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences; Jiangsu Technical Service Center of Diagnosis and Detection for Plant Virus Diseases, Nanjing 210014, People's Republic of China
| | - Tong Zhou
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences; Jiangsu Technical Service Center of Diagnosis and Detection for Plant Virus Diseases, Nanjing 210014, People's Republic of China
| | - Yinghua Ji
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences; Jiangsu Technical Service Center of Diagnosis and Detection for Plant Virus Diseases, Nanjing 210014, People's Republic of China
| | - Jinhua Deng
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences; Jiangsu Technical Service Center of Diagnosis and Detection for Plant Virus Diseases, Nanjing 210014, People's Republic of China
| | - Sek-Man Wong
- National University of Singapore Suzhou Research Institute, Suzhou 215123, People's Republic of China
| | - Yijun Zhou
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences; Jiangsu Technical Service Center of Diagnosis and Detection for Plant Virus Diseases, Nanjing 210014, People's Republic of China
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Glial enriched gene expression profiling identifies novel factors regulating the proliferation of specific glial subtypes in the Drosophila brain. Gene Expr Patterns 2014; 16:61-8. [PMID: 25217886 PMCID: PMC4222725 DOI: 10.1016/j.gep.2014.09.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 09/02/2014] [Accepted: 09/04/2014] [Indexed: 01/13/2023]
Abstract
Global gene expression analysis identifies glial specific transcriptomes. Different glial subtypes have distinct but overlapping transcriptomes. foxO and tramtrack69 are novel regulators of glial subtype specific proliferation.
Glial cells constitute a large proportion of the central nervous system (CNS) and are critical for the correct development and function of the adult CNS. Recent studies have shown that specific subtypes of glia are generated through the proliferation of differentiated glial cells in both the developing invertebrate and vertebrate nervous systems. However, the factors that regulate glial proliferation in specific glial subtypes are poorly understood. To address this we have performed global gene expression analysis of Drosophila post-embryonic CNS tissue enriched in glial cells, through glial specific overexpression of either the FGF or insulin receptor. Analysis of the differentially regulated genes in these tissues shows that the expression of known glial genes is significantly increased in both cases. Conversely, the expression of neuronal genes is significantly decreased. FGF and insulin signalling drive the expression of overlapping sets of genes in glial cells that then activate proliferation. We then used these data to identify novel transcription factors that are expressed in glia in the brain. We show that two of the transcription factors identified in the glial enriched gene expression profiles, foxO and tramtrack69, have novel roles in regulating the proliferation of cortex and perineurial glia. These studies provide new insight into the genes and molecular pathways that regulate the proliferation of specific glial subtypes in the Drosophila post-embryonic brain.
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69
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Igaki T, Miura M. The Drosophila TNF ortholog Eiger: emerging physiological roles and evolution of the TNF system. Semin Immunol 2014; 26:267-74. [PMID: 24981286 DOI: 10.1016/j.smim.2014.05.003] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 05/22/2014] [Indexed: 12/19/2022]
Abstract
The TNF and TNFR superfamilies of proteins are conserved throughout evolution. The first invertebrate orthologs of TNF and TNFR, Eiger and Wengen, were identified in Drosophila, which enabled us to take advantage of its powerful genetics. Indeed, genetic studies on Eiger in the last decade have discovered their signaling mechanisms through activation of the JNK pathway and unveiled the role of Eiger-JNK signaling in a variety of cellular and tissue processes such as cell death, cell proliferation, tissue growth regulation, host defense, pain sensitization, and canalization. In this review, we will describe the in vivo signaling of Eiger and its physiological roles in fly development and homeostasis, and will discuss the evolution of the TNF/TNFR systems.
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Affiliation(s)
- Tatsushi Igaki
- Laboratory of Genetics, Graduate School of Biostudies, Kyoto University, Yoshida-Konoecho, Sakyo-ku, Kyoto 606-8501, Japan; Precursory Research for Embryonic Science and Technology (PRESTO), Basic Research Program, Japan Science and Technology Agency, Chiyoda-ku, Tokyo 102-0075, Japan.
| | - Masayuki Miura
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan; Core Research for Evolutional Science and Technology (CREST), Basic Research Program, Japan Science and Technology Agency, Chiyoda-ku, Tokyo 102-0075, Japan.
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70
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Stein DS, Stevens LM. Maternal control of the Drosophila dorsal-ventral body axis. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2014; 3:301-30. [PMID: 25124754 DOI: 10.1002/wdev.138] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Revised: 03/24/2014] [Accepted: 04/07/2014] [Indexed: 12/14/2022]
Abstract
UNLABELLED The pathway that generates the dorsal-ventral (DV) axis of the Drosophila embryo has been the subject of intense investigation over the previous three decades. The initial asymmetric signal originates during oogenesis by the movement of the oocyte nucleus to an anterior corner of the oocyte, which establishes DV polarity within the follicle through signaling between Gurken, the Drosophila Transforming Growth Factor (TGF)-α homologue secreted from the oocyte, and the Drosophila Epidermal Growth Factor Receptor (EGFR) that is expressed by the follicular epithelium cells that envelop the oocyte. Follicle cells that are not exposed to Gurken follow a ventral fate and express Pipe, a sulfotransferase that enzymatically modifies components of the inner vitelline membrane layer of the eggshell, thereby transferring DV spatial information from the follicle to the egg. These ventrally sulfated eggshell proteins comprise a localized cue that directs the ventrally restricted formation of the active Spätzle ligand within the perivitelline space between the eggshell and the embryonic membrane. Spätzle activates Toll, a transmembrane receptor in the embryonic membrane. Transmission of the Toll signal into the embryo leads to the formation of a ventral-to-dorsal gradient of the transcription factor Dorsal within the nuclei of the syncytial blastoderm stage embryo. Dorsal controls the spatially specific expression of a large constellation of zygotic target genes, the Dorsal gene regulatory network, along the embryonic DV circumference. This article reviews classic studies and integrates them with the details of more recent work that has advanced our understanding of the complex pathway that establishes Drosophila embryo DV polarity. For further resources related to this article, please visit the WIREs website. CONFLICT OF INTEREST The authors have declared no conflicts of interest for this article.
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Affiliation(s)
- David S Stein
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
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71
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Abstract
The construction and prediction of cell fate maps at the whole embryo level require the establishment of an accurate atlas of gene expression patterns throughout development and the identification of the corresponding cis-regulatory sequences. However, while the expression and regulation of genes encoding upstream developmental regulators such as transcription factors or signaling pathway components have been analyzed in detail, up to date the number of cis-regulatory sequences identified for downstream effector genes, like ion channels, pumps and exchangers, is very low. The control and regulation of ion homeostasis in each cell, including at blastoderm stages, are essential for normal embryonic development. In this study, we analyzed in detail the embryonic expression pattern and cis-regulatory modules of the Drosophila Na+-driven anion exchanger 1 (Ndae1) gene, involved in the regulation of pH homeostasis. We show that Ndae1 is expressed in a tight and complex spatial-temporal pattern. In particular, we report that this downstream effector gene is under the control of the canonical dorsal-ventral patterning cascade through dorsal, Toll, twist and snail at early embryogenesis. Moreover, we identify several cis-regulatory modules, some of which control discrete and non-overlapping aspects of endogenous gene expression throughout development.
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Zehavi Y, Kuznetsov O, Ovadia-Shochat A, Juven-Gershon T. Core promoter functions in the regulation of gene expression of Drosophila dorsal target genes. J Biol Chem 2014; 289:11993-12004. [PMID: 24634215 DOI: 10.1074/jbc.m114.550251] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Developmental processes are highly dependent on transcriptional regulation by RNA polymerase II. The RNA polymerase II core promoter is the ultimate target of a multitude of transcription factors that control transcription initiation. Core promoters consist of core promoter motifs, e.g. the initiator, TATA box, and the downstream core promoter element (DPE), which confer specific properties to the core promoter. Here, we explored the importance of core promoter functions in the dorsal-ventral developmental gene regulatory network. This network includes multiple genes that are activated by different nuclear concentrations of Dorsal, an NFκB homolog transcription factor, along the dorsal-ventral axis. We show that over two-thirds of Dorsal target genes contain DPE sequence motifs, which is significantly higher than the proportion of DPE-containing promoters in Drosophila genes. We demonstrate that multiple Dorsal target genes are evolutionarily conserved and functionally dependent on the DPE. Furthermore, we have analyzed the activation of key Dorsal target genes by Dorsal, as well as by another Rel family transcription factor, Relish, and the dependence of their activation on the DPE motif. Using hybrid enhancer-promoter constructs in Drosophila cells and embryo extracts, we have demonstrated that the core promoter composition is an important determinant of transcriptional activity of Dorsal target genes. Taken together, our results provide evidence for the importance of core promoter composition in the regulation of Dorsal target genes.
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Affiliation(s)
- Yonathan Zehavi
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Olga Kuznetsov
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Avital Ovadia-Shochat
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Tamar Juven-Gershon
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 52900, Israel.
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73
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Identification of a novel interacting partner of the chemosensory protein 1 from Plutella xylostella L. Int J Biol Macromol 2014; 63:233-9. [DOI: 10.1016/j.ijbiomac.2013.09.037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 06/27/2013] [Accepted: 09/24/2013] [Indexed: 11/24/2022]
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74
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Lindsay SA, Wasserman SA. Conventional and non-conventional Drosophila Toll signaling. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2014; 42:16-24. [PMID: 23632253 PMCID: PMC3787077 DOI: 10.1016/j.dci.2013.04.011] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 04/17/2013] [Accepted: 04/17/2013] [Indexed: 05/07/2023]
Abstract
The discovery of Toll in Drosophila and of the remarkable conservation in pathway composition and organization catalyzed a transformation in our understanding of innate immune recognition and response. At the center of that picture is a cascade of interactions in which specific microbial cues activate Toll receptors, which then transmit signals driving transcription factor nuclear localization and activity. Experiments gave substance to the vision of pattern recognition receptors, linked phenomena in development, gene regulation, and immunity into a coherent whole, and revealed a rich set of variations for identifying non-self and responding effectively. More recently, research in Drosophila has illuminated the positive and negative regulation of Toll activation, the organization of signaling events at and beneath membranes, the sorting of information flow, and the existence of non-conventional signaling via Toll-related receptors. Here, we provide an overview of the Toll pathway of flies and highlight these ongoing realms of research.
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Affiliation(s)
- Scott A. Lindsay
- Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, California 92093-0349, USA
| | - Steven A. Wasserman
- Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, California 92093-0349, USA
- Corresponding author. Tel: 858-822-2408.
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Hodar C, Zuñiga A, Pulgar R, Travisany D, Chacon C, Pino M, Maass A, Cambiazo V. Comparative gene expression analysis of Dtg, a novel target gene of Dpp signaling pathway in the early Drosophila melanogaster embryo. Gene 2013; 535:210-7. [PMID: 24321690 DOI: 10.1016/j.gene.2013.11.032] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 10/30/2013] [Accepted: 11/14/2013] [Indexed: 10/25/2022]
Abstract
In the early Drosophila melanogaster embryo, Dpp, a secreted molecule that belongs to the TGF-β superfamily of growth factors, activates a set of downstream genes to subdivide the dorsal region into amnioserosa and dorsal epidermis. Here, we examined the expression pattern and transcriptional regulation of Dtg, a new target gene of Dpp signaling pathway that is required for proper amnioserosa differentiation. We showed that the expression of Dtg was controlled by Dpp and characterized a 524-bp enhancer that mediated expression in the dorsal midline, as well as, in the differentiated amnioserosa in transgenic reporter embryos. This enhancer contained a highly conserved region of 48-bp in which bioinformatic predictions and in vitro assays identified three Mad binding motifs. Mutational analysis revealed that these three motifs were necessary for proper expression of a reporter gene in transgenic embryos, suggesting that short and highly conserved genomic sequences may be indicative of functional regulatory regions in D. melanogaster genes. Dtg orthologs were not detected in basal lineages of Dipterans, which unlike D. melanogaster develop two extra-embryonic membranes, amnion and serosa, nevertheless Dtg orthologs were identified in the transcriptome of Musca domestica, in which dorsal ectoderm patterning leads to the formation of a single extra-embryonic membrane. These results suggest that Dtg was recruited as a new component of the network that controls dorsal ectoderm patterning in the lineage leading to higher Cyclorrhaphan flies, such as D. melanogaster and M. domestica.
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Affiliation(s)
- Christian Hodar
- Laboratorio de Bioinformática y Expresión Génica, INTA-Universidad de Chile, El Líbano 5524, Santiago, Chile; Fondap Center for Genome Regulation (CGR), Universidad de Chile, Santiago, Chile
| | - Alejandro Zuñiga
- Laboratorio de Bioinformática y Expresión Génica, INTA-Universidad de Chile, El Líbano 5524, Santiago, Chile; Fondap Center for Genome Regulation (CGR), Universidad de Chile, Santiago, Chile
| | - Rodrigo Pulgar
- Laboratorio de Bioinformática y Expresión Génica, INTA-Universidad de Chile, El Líbano 5524, Santiago, Chile; Fondap Center for Genome Regulation (CGR), Universidad de Chile, Santiago, Chile
| | - Dante Travisany
- Laboratorio de Bioinformática y Matemática del Genoma, Center for Mathematical Modeling, FCFM-Universidad de Chile, Santiago, Chile; Fondap Center for Genome Regulation (CGR), Universidad de Chile, Santiago, Chile
| | - Carlos Chacon
- Laboratorio de Bioinformática y Expresión Génica, INTA-Universidad de Chile, El Líbano 5524, Santiago, Chile
| | - Michael Pino
- Laboratorio de Bioinformática y Expresión Génica, INTA-Universidad de Chile, El Líbano 5524, Santiago, Chile
| | - Alejandro Maass
- Laboratorio de Bioinformática y Matemática del Genoma, Center for Mathematical Modeling, FCFM-Universidad de Chile, Santiago, Chile; Fondap Center for Genome Regulation (CGR), Universidad de Chile, Santiago, Chile; Department of Mathematical Engineering, FCFM-Universidad de Chile, Santiago, Chile
| | - Verónica Cambiazo
- Laboratorio de Bioinformática y Expresión Génica, INTA-Universidad de Chile, El Líbano 5524, Santiago, Chile; Fondap Center for Genome Regulation (CGR), Universidad de Chile, Santiago, Chile.
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76
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Gavin-Smyth J, Wang YC, Butler I, Ferguson EL. A genetic network conferring canalization to a bistable patterning system in Drosophila. Curr Biol 2013; 23:2296-2302. [PMID: 24184102 PMCID: PMC4495911 DOI: 10.1016/j.cub.2013.09.055] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 09/03/2013] [Accepted: 09/24/2013] [Indexed: 01/19/2023]
Abstract
To achieve the "constancy of the wild-type," the developing organism must be buffered against stochastic fluctuations and environmental perturbations. This phenotypic buffering has been theorized to arise from a variety of genetic mechanisms and is widely thought to be adaptive and essential for viability. In the Drosophila blastoderm embryo, staining with antibodies against the active, phosphorylated form of the bone morphogenetic protein (BMP) signal transducer Mad, pMad, or visualization of the spatial pattern of BMP-receptor interactions reveals a spatially bistable pattern of BMP signaling centered on the dorsal midline. This signaling event is essential for the specification of dorsal cell fates, including the extraembryonic amnioserosa. BMP signaling is initiated by facilitated extracellular diffusion that localizes BMP ligands dorsally. BMP signaling then activates an intracellular positive feedback circuit that promotes future BMP-receptor interactions. Here, we identify a genetic network comprising three genes that canalizes this BMP signaling event. The BMP target eiger (egr) acts in the positive feedback circuit to promote signaling, while the BMP binding protein encoded by crossveinless-2 (cv-2) antagonizes signaling. Expression of both genes requires the early activity of the homeobox gene zerknüllt (zen). Two Drosophila species lacking early zen expression have high variability in BMP signaling. These data both detail a new mechanism that generates developmental canalization and identify an example of a species with noncanalized axial patterning.
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Affiliation(s)
- Jackie Gavin-Smyth
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Yu-Chiun Wang
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637, USA
| | - Ian Butler
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Edwin L Ferguson
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA; Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637, USA.
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77
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Buchta T, Özüak O, Stappert D, Roth S, Lynch JA. Patterning the dorsal–ventral axis of the wasp Nasonia vitripennis. Dev Biol 2013; 381:189-202. [DOI: 10.1016/j.ydbio.2013.05.026] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 05/14/2013] [Accepted: 05/24/2013] [Indexed: 10/26/2022]
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78
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Stein D, Cho YS, Stevens LM. Localized serine protease activity and the establishment of Drosophila embryonic dorsoventral polarity. Fly (Austin) 2013; 7:161-7. [PMID: 24047959 DOI: 10.4161/fly.25141] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Drosophila embryo dorsoventral polarity is established by a maternally encoded signal transduction pathway in which three sequentially acting serine proteases, Gastrulation Defective, Snake and Easter, generate the ligand that activates the Toll receptor on the ventral side of the embryo. The spatial regulation of this pathway depends upon ventrally restricted expression of the Pipe sulfotransferase in the ovarian follicle during egg formation. Several recent observations have advanced our understanding of the mechanism regulating the spatially restricted activation of Toll. First, several protein components of the vitelline membrane layer of the eggshell have been determined to be targets of Pipe-mediated sulfation. Second, the processing of Easter by Snake has been identified as the first Pipe-dependent, ventrally-restricted processing event in the pathway. Finally, Gastrulation Defective has been shown to undergo Pipe-dependent, ventral localization within the perivitelline space and to facilitate Snake-mediated processing of Easter. Together, these observations suggest that Gastrulation Defective, localized on the interior ventral surface of the eggshell in association with Pipe-sulfated eggshell proteins, recruits and mediates an interaction between Snake and Easter. This event leads to ventrally-restricted processing and activation of Easter and consequently, localized formation of the Toll ligand, and Toll activation.
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Affiliation(s)
- David Stein
- Section of Molecular Cell and Developmental Biology; Institute for Cellular and Molecular Biology; University of Texas at Austin; Austin, TX USA
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79
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Kim Y, Iagovitina A, Ishihara K, Fitzgerald KM, Deplancke B, Papatsenko D, Shvartsman SY. Context-dependent transcriptional interpretation of mitogen activated protein kinase signaling in the Drosophila embryo. CHAOS (WOODBURY, N.Y.) 2013; 23:025105. [PMID: 23822503 PMCID: PMC3689791 DOI: 10.1063/1.4808157] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 05/07/2013] [Indexed: 06/02/2023]
Abstract
Terminal regions of the Drosophila embryo are patterned by the localized activation of Mitogen Activated Protein Kinase (MAPK), which induces zygotic genes through relief of their repression by transcriptional repressor Capicua. The levels of MAPK activation at the anterior and posterior termini are close to each other, but the expression patterns of MAPK-target genes, such as zerknüllt (zen) and tailless (tll), display strong anterior-posterior (AP) asymmetry. This region-specific response to MAPK activation provides a clear example of context-dependent interpretation of inductive signaling, a common developmental effect that remains poorly understood. In the past, the AP asymmetry of zen expression was attributed to a mechanism that depends on MAPK substrate competition. We present data suggesting that the asymmetric expression of tll is generated by a different mechanism, based on feedforward control and multiple enhancers of the tll gene. A simple mathematical model of this mechanism correctly predicts how the wild-type expression pattern of tll changes in mutants affecting the anterior, dorsoventral, and terminal patterning systems and some of their direct targets.
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Affiliation(s)
- Yoosik Kim
- Department of Chemical and Biological Engineering and Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544, USA
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80
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Kulmuni J, Havukainen H. Insights into the evolution of the CSP gene family through the integration of evolutionary analysis and comparative protein modeling. PLoS One 2013; 8:e63688. [PMID: 23723994 PMCID: PMC3665776 DOI: 10.1371/journal.pone.0063688] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 04/05/2013] [Indexed: 01/10/2023] Open
Abstract
Insect chemical communication and chemosensory systems rely on proteins coded by several gene families. Here, we have combined protein modeling with evolutionary analysis in order to study the evolution and structure of chemosensory proteins (CSPs) within arthropods and, more specifically, in ants by using the data available from sequenced genomes. Ants and other social insects are especially interesting model systems for the study of chemosensation, as they communicate in a highly complex social context and much of their communication relies on chemicals. Our ant protein models show how this complexity has shaped CSP evolution; the proteins are highly modifiable by their size, surface charge and binding pocket. Based on these findings, we divide ant CSPs into three groups: typical insect CSPs, an ancient 5-helical CSP and hymenopteran CSPs with a small binding pocket, and suggest that these groups likely serve different functions. The hymenopteran CSPs have duplicated repeatedly in individual ant lineages. In these CSPs, positive selection has driven surface charge changes, an observation which has possible implications for the interaction between CSPs and ligands or odorant receptors. Our phylogenetic analysis shows that within the Arthropoda the only highly conserved gene is the ancient 5-helical CSP, which is likely involved in an essential ubiquitous function rather than chemosensation. During insect evolution, the 6-helical CSPs have diverged and perform chemosensory functions among others. Our results contribute to the general knowledge of the structural differences between proteins underlying chemosensation and highlight those protein properties which have been affected by adaptive evolution.
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Affiliation(s)
- Jonna Kulmuni
- Department of Biology and Biocenter Oulu, University of Oulu, Oulu, Finland.
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81
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Hong JW, Park KW, Levine MS. Temporal regulation of single-minded target genes in the ventral midline of the Drosophila central nervous system. Dev Biol 2013; 380:335-43. [PMID: 23701883 DOI: 10.1016/j.ydbio.2013.05.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 05/11/2013] [Accepted: 05/13/2013] [Indexed: 12/21/2022]
Abstract
Differentiation of a specific organ or tissue requires sequential activation of regulatory genes. However, little is known about how serial gene expression is temporally regulated. Here, we present evidence that differential expression of single-minded (sim) target genes can be attributed, in part, to the number of Sim and Tango (Tgo) heterodimer binding sites within their enhancer regions. The Sim, termed a master regulator, directs ventral midline differentiation of Drosophila central nervous system (CNS). According to data on the onset timing of ventral midline gene expression, sim target genes are classified into at least 2 groups (early and late). The sim and rhomboid (rho) genes are activated during early midline differentiation whereas orthodenticle (otd), CG10249, and slit (sli) genes undergo activation during later stages of midline differentiation. Germline transformation and in situ hybridization with transgenic embryos demonstrate that enhancers activating sim and rho expression contain 4 Sim-Tgo binding sites whereas only 1 Sim-Tgo binding site is found in an enhancer of sli. A mutagenized version of the rho enhancer lacking either 1, 2, or 3 Sim-Tgo binding sites mediated progressively more delayed expression of a lacZ reporter gene in the ventral midline. In contrast, a modified sli enhancer displayed progressively earlier onset of lacZ expression when 1, 2, or 3 more Sim-Tgo binding sites were added. Taken together, these results suggest that the number of Sim-Tgo-binding sites is decisive in determining the timing of gene expression in the developing ventral midline. We also discuss a combinatorial model accounting for the sequential expression of sim target genes.
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Affiliation(s)
- Joung-Woo Hong
- Graduate School of East-West Medical Science, Kyung Hee University, Yongin 446-701, South Korea.
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82
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Ly LL, Suyari O, Yoshioka Y, Tue NT, Yoshida H, Yamaguchi M. dNF-YB plays dual roles in cell death and cell differentiation during Drosophila eye development. Gene 2013; 520:106-18. [DOI: 10.1016/j.gene.2013.02.036] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 02/16/2013] [Accepted: 02/23/2013] [Indexed: 11/16/2022]
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83
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Nestorov P, Battke F, Levesque MP, Gerberding M. The maternal transcriptome of the crustacean Parhyale hawaiensis is inherited asymmetrically to invariant cell lineages of the ectoderm and mesoderm. PLoS One 2013; 8:e56049. [PMID: 23418507 PMCID: PMC3572164 DOI: 10.1371/journal.pone.0056049] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 01/04/2013] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The embryo of the crustacean Parhyale hawaiensis has a total, unequal and invariant early cleavage pattern. It specifies cell fates earlier than other arthropods, including Drosophila, as individual blastomeres of the 8-cell stage are allocated to the germ layers and the germline. Furthermore, the 8-cell stage is amenable to embryological manipulations. These unique features make Parhyale a suitable system for elucidating germ layer specification in arthropods. Since asymmetric localization of maternally provided RNA is a widespread mechanism to specify early cell fates, we asked whether this is also true for Parhyale. A candidate gene approach did not find RNAs that are asymmetrically distributed at the 8-cell stage. Therefore, we designed a high-density microarray from 9400 recently sequenced ESTs (1) to identify maternally provided RNAs and (2) to find RNAs that are differentially distributed among cells of the 8-cell stage. RESULTS Maternal-zygotic transition takes place around the 32-cell stage, i.e. after the specification of germ layers. By comparing a pool of RNAs from early embryos without zygotic transcription to zygotic RNAs of the germband, we found that more than 10% of the targets on the array were enriched in the maternal transcript pool. A screen for asymmetrically distributed RNAs at the 8-cell stage revealed 129 transcripts, from which 50% are predominantly expressed in the early embryonic stages. Finally, we performed knockdown experiments for two of these genes and observed cell-fate-related defects of embryonic development. CONCLUSIONS In contrast to Drosophila, the four primary germ layer cell lineages in Parhyale are specified during the maternal control phase of the embryo. A key step in this process is the asymmetric distribution of a large number of maternal RNAs to the germ layer progenitor cells.
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Affiliation(s)
- Peter Nestorov
- Max Planck Institut für Entwicklungsbiologie, Tübingen, Germany
| | - Florian Battke
- Center for Bioinformatics, University of Tübingen, Tübingen, Germany
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84
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Genome-wide screens for in vivo Tinman binding sites identify cardiac enhancers with diverse functional architectures. PLoS Genet 2013; 9:e1003195. [PMID: 23326246 PMCID: PMC3542182 DOI: 10.1371/journal.pgen.1003195] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2012] [Accepted: 11/08/2012] [Indexed: 12/20/2022] Open
Abstract
The NK homeodomain factor Tinman is a crucial regulator of early mesoderm patterning and, together with the GATA factor Pannier and the Dorsocross T-box factors, serves as one of the key cardiogenic factors during specification and differentiation of heart cells. Although the basic framework of regulatory interactions driving heart development has been worked out, only about a dozen genes involved in heart development have been designated as direct Tinman target genes to date, and detailed information about the functional architectures of their cardiac enhancers is lacking. We have used immunoprecipitation of chromatin (ChIP) from embryos at two different stages of early cardiogenesis to obtain a global overview of the sequences bound by Tinman in vivo and their linked genes. Our data from the analysis of ∼50 sequences with high Tinman occupancy show that the majority of such sequences act as enhancers in various mesodermal tissues in which Tinman is active. All of the dorsal mesodermal and cardiac enhancers, but not some of the others, require tinman function. The cardiac enhancers feature diverse arrangements of binding motifs for Tinman, Pannier, and Dorsocross. By employing these cardiac and non-cardiac enhancers in machine learning approaches, we identify a novel motif, termed CEE, as a classifier for cardiac enhancers. In vivo assays for the requirement of the binding motifs of Tinman, Pannier, and Dorsocross, as well as the CEE motifs in a set of cardiac enhancers, show that the Tinman sites are essential in all but one of the tested enhancers; although on occasion they can be functionally redundant with Dorsocross sites. The enhancers differ widely with respect to their requirement for Pannier, Dorsocross, and CEE sites, which we ascribe to their different position in the regulatory circuitry, their distinct temporal and spatial activities during cardiogenesis, and functional redundancies among different factor binding sites. The Drosophila homeodomain protein Tinman was the first transcription factor found to control the development and differentiation of the heart in any species. In spite of that, our knowledge of the number, identities, and mode of regulation of the downstream target genes of Tinman that are necessary to exert its cardiogenic functions is still very incomplete. To address these issues, we have performed a genome-wide analysis of DNA regions associated with Tinman-binding in embryos and the genes linked to them. The combined data from our in-depth in vivo assays of sequence elements with high Tinman occupancy allow the following general conclusions: (1) The majority of such sequences are active as regulatory elements (called enhancers) in mesodermal tissues that include Tinman-expressing cells. (2) The enhancers active in the heart progenitor cells and the heart generally are dependent on tinman gene activity, whereas those active in non-cardiac mesoderm are often bound neutrally by Tinman. (3) Tinman binding motifs in most cases are essential for cardiac enhancer activity, but in some cases they can be functionally-redundant with those of other cardiogenic factors. (4) Tinman-occupied cardiac enhancers are enriched for a newly discovered binding motif for an unknown factor that is functional in vivo.
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85
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Hou CX, Qin GX, Liu T, Mei XL, Li B, Shen ZY, Guo XJ. Differentially expressed genes in the cuticle and hemolymph of the silkworm, Bombyx mori, injected with the fungus Beauveria bassiana. JOURNAL OF INSECT SCIENCE (ONLINE) 2013; 13:138. [PMID: 24794288 PMCID: PMC4015409 DOI: 10.1673/031.013.13801] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 08/06/2013] [Indexed: 06/03/2023]
Abstract
The most important pathogenic fungus of the silkworm, Bombyx mori L. (Lepidoptera: Bombycidae), is Beauveria bassiana (Balsamo-Crivelli ) Vuillemin (Hypocreales: Clavicipitaceae), which causes significant damage to sericulture production. Therefore, diagnosing fungal disease and developing new control measures are crucial to silk production. To better understand the responsive and interactive mechanisms between the host silkworm and this fungus, variations in silkworm gene expression were investigated using the suppression subtractive hybridization method following the injection of B. bassiana conidia. Two cDNA libraries were constructed, and 140 cDNA clones were isolated. Of the 50 differentially expressed genes identified, 45 (112 clones) were identified in the forward library, and 5 (28 clones) were identified in the reverse library. Expression profiling of six of these genes by quantitative polymerase chain reaction (qPCR) verified that they were induced by the fungal challenge. The present study provides insight into the interaction between lepidopteran insects and pathogenic fungi.
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Affiliation(s)
- Cheng-Xiang Hou
- Sericultural Research Institute, Jiangsu University of Science and Technology, Zhenjiang 212003, Jiangsu, China
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture of China, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212018, Jiangsu, China
| | - Guang-Xing Qin
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture of China, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212018, Jiangsu, China
| | - Ting Liu
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture of China, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212018, Jiangsu, China
| | - Xing-Lin Mei
- Sericultural Research Institute, Jiangsu University of Science and Technology, Zhenjiang 212003, Jiangsu, China
| | - Bing Li
- Sericultural Research Institute, Jiangsu University of Science and Technology, Zhenjiang 212003, Jiangsu, China
| | - Zhong-Yuan Shen
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture of China, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212018, Jiangsu, China
| | - Xi-Jie Guo
- Sericultural Research Institute, Jiangsu University of Science and Technology, Zhenjiang 212003, Jiangsu, China
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture of China, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212018, Jiangsu, China
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86
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Park KW, Hong JW. Mesodermal repression of single-minded in Drosophila embryo is mediated by a cluster of Snail-binding sites proximal to the early promoter. BMB Rep 2012; 45:577-82. [PMID: 23101512 DOI: 10.5483/bmbrep.2012.45.10.105] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
single-minded (sim) is a master regulatory gene that directs differentiation in the central nervous system during Drosophila embryogenesis. Recent identification of the mesectoderm enhancer (MSE) of sim has led to the hypothesis that two Snail (Sna)-binding sites in the MSE may repress sim expression in the presumptive mesoderm. We provide evidence here that three Sna-binding sites proximal to the sim promoter, but not those of the MSE, are responsible for the mesodermal repression of sim in vivo. Using transgenic embryos injected with lacZ transgenes, we showed that sim repression in the mesoderm requires the three promoter-proximal Sna-binding sites. These results suggest that Sna represses the mesectodermal expression of sim by directly repressing the nearby promoter, and not by quenching adjacent transcriptional activators in the MSE. These data also showed how the MSE, lacking the three proximal Sna-binding sites, reproduced the endogenous pattern of sim expression in transgenic embryos.
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Affiliation(s)
- Kye Won Park
- Department of Food Science and Biotechnology, Sungkyunkwan University, Suwon, Korea
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87
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Gong L, Luo Q, Rizwan-ul-Haq M, Hu MY. Cloning and characterization of three chemosensory proteins from Spodoptera exigua and effects of gene silencing on female survival and reproduction. BULLETIN OF ENTOMOLOGICAL RESEARCH 2012; 102:600-609. [PMID: 22475511 DOI: 10.1017/s0007485312000168] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Insect chemosensory proteins (CSPs) are supposed to transport hydrophobic chemicals to receptors on sensory neurons. However, CSPs are broadly expressed in various insect tissues, suggesting their involvement in the physiological processes beyond chemoreception. So, the exact physiological roles of CSPs in insects still need to be unraveled. In this study, three full-length of CSP genes from Spodoptera exigua have been cloned and characterized. The deduced amino acid sequences of SexiCSP1, SexiCSP2 and SexiCSP3 revealed open reading frames of 128, 128 and 126 amino acids, respectively, with four conserved cysteine residues. The expression patterns of the three SexiCSPs were further investigated by real-time PCR. Three SexiCSPs were expressed in antennae, heads, legs, wings, thoraxes, abdomens, testes and ovaries, with the highest expression level in female and male antennae. Furthermore, all three SexiCSPs mRNA were distributed extensively in the tested development stages with the highest expression level in pupae. RNAi-based gene silencing study resulted in a dramatic reduction of corresponding mRNA in female S. exigua after injection with dsRNA of all three SexiCSPs. Consequentially, 42.5% of mortalities, 68.3% (compare to DEPC water injected control) and 71.4% (compare to uninjected control) oviposition inhibition, and significantly effected egg hatching were observed in the female S. exigua injected with dsSexiCSP3 as compared to control treatments. On the other hand, dsSexiCSP1 and dsSexiCSP2 injected female adults did not show effects on survival and reproduction. Our study confirms the utility of RNAi approach to functional characterization of CSP genes in S. exigua and provides a starting point for further studies on female survival and reproduction in this insect. It also reveals the potential pest controlling method, as insect behavior regulation agent that disrupts the expression of chemosensory proteins.
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Affiliation(s)
- L Gong
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, P.R. China, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, Guangdong Province, China
| | - Q Luo
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, P.R. China, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, Guangdong Province, China
| | - M Rizwan-ul-Haq
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, P.R. China, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, Guangdong Province, China
| | - M-Y Hu
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, P.R. China, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, Guangdong Province, China
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88
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Simonova OB, Modestova EA, Vorontsova JE, Cherezov RO. Screening of genomic regions affecting lawc/Trf2 gene expression during Drosophila melanogaster development. Russ J Dev Biol 2012. [DOI: 10.1134/s1062360412050086] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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89
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Abstract
The vast majority of research on nuclear factor κB (NF-κB) signaling in the past 25 years has focused on its roles in normal and disease-related processes in vertebrates, especially mice and humans. Recent genome and transcriptome sequencing efforts have shown that homologs of NF-κB transcription factors, inhibitor of NF-κB (IκB) proteins, and IκB kinases are present in a variety of invertebrates, including several in phyla simpler than Arthropoda, the phylum containing insects such Drosophila. Moreover, many invertebrates also contain genes encoding homologs of upstream signaling proteins in the Toll-like receptor signaling pathway, which is well-known for its downstream activation of NF-κB for innate immunity. This review describes what we now know or can infer and speculate about the evolution of the core elements of NF-κB signaling as well as the biological processes controlled by NF-κB in invertebrates. Further research on NF-κB in invertebrates is likely to uncover information about the evolutionary origins of this key human signaling pathway and may have relevance to our management of the responses of ecologically and economically important organisms to environmental and adaptive pressures.
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Affiliation(s)
- Thomas D Gilmore
- Department of Biology, Boston University, Boston, MA 02215, USA.
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90
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Holmqvist PH, Boija A, Philip P, Crona F, Stenberg P, Mannervik M. Preferential genome targeting of the CBP co-activator by Rel and Smad proteins in early Drosophila melanogaster embryos. PLoS Genet 2012; 8:e1002769. [PMID: 22737084 PMCID: PMC3380834 DOI: 10.1371/journal.pgen.1002769] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 05/02/2012] [Indexed: 11/18/2022] Open
Abstract
CBP and the related p300 protein are widely used transcriptional co-activators in metazoans that interact with multiple transcription factors. Whether CBP/p300 occupies the genome equally with all factors or preferentially binds together with some factors is not known. We therefore compared Drosophila melanogaster CBP (nejire) ChIP-seq peaks with regions bound by 40 different transcription factors in early embryos, and we found high co-occupancy with the Rel-family protein Dorsal. Dorsal is required for CBP occupancy in the embryo, but only at regions where few other factors are present. CBP peaks in mutant embryos lacking nuclear Dorsal are best correlated with TGF-ß/Dpp-signaling and Smad-protein binding. Differences in CBP occupancy in mutant embryos reflect gene expression changes genome-wide, but CBP also occupies some non-expressed genes. The presence of CBP at silent genes does not result in histone acetylation. We find that Polycomb-repressed H3K27me3 chromatin does not preclude CBP binding, but restricts histone acetylation at CBP-bound genomic sites. We conclude that CBP occupancy in Drosophila embryos preferentially overlaps factors controlling dorso-ventral patterning and that CBP binds silent genes without causing histone hyperacetylation.
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Affiliation(s)
- Per-Henrik Holmqvist
- The Wenner-Gren Institute, Developmental Biology, Stockholm University, Stockholm, Sweden
| | - Ann Boija
- The Wenner-Gren Institute, Developmental Biology, Stockholm University, Stockholm, Sweden
| | - Philge Philip
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Computational Life Science Cluster (CLiC), Umeå University, Umeå, Sweden
| | - Filip Crona
- The Wenner-Gren Institute, Developmental Biology, Stockholm University, Stockholm, Sweden
| | - Per Stenberg
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Computational Life Science Cluster (CLiC), Umeå University, Umeå, Sweden
- * E-mail: (MM); (PS)
| | - Mattias Mannervik
- The Wenner-Gren Institute, Developmental Biology, Stockholm University, Stockholm, Sweden
- * E-mail: (MM); (PS)
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91
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Transcriptional repression via antilooping in the Drosophila embryo. Proc Natl Acad Sci U S A 2012; 109:9460-4. [PMID: 22645339 DOI: 10.1073/pnas.1102625108] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Transcriptional repressors are thought to inhibit gene expression by interfering with the binding or function of RNA Polymerase II, perhaps by promoting local chromatin condensation. Here, we present evidence for a distinctive mechanism of repression, whereby sequence-specific repressors prevent the looping of distal enhancers to the promoter. Particular efforts focus on the Snail repressor, which plays a conserved role in promoting epithelial-mesenchyme transitions in both invertebrates and vertebrates, including mesoderm invagination in Drosophila, neural crest migration in vertebrates, and tumorigenesis in mammals. Chromosome conformation capture experiments were used to examine enhancer looping at Snail target genes in wild-type and mutant embryos. These studies suggest that the Snail repressor blocks the formation of fruitful enhancer-promoter interactions when bound to a distal enhancer. This higher-order mechanism of transcriptional repression has broad implications for the control of gene activity in metazoan development.
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92
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El-Sherif E, Lynch JA, Brown SJ. Comparisons of the embryonic development of Drosophila, Nasonia, and Tribolium. WILEY INTERDISCIPLINARY REVIEWS. DEVELOPMENTAL BIOLOGY 2012; 1:16-39. [PMID: 23801665 PMCID: PMC5323069 DOI: 10.1002/wdev.3] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Studying the embryogenesis of diverse insect species is crucial to understanding insect evolution. Here, we review current advances in understanding the development of two emerging model organisms: the wasp Nasonia vitripennis and the beetle Tribolium castaneum in comparison with the well-studied fruit fly Drosophila melanogaster. Although Nasonia represents the most basally branching order of holometabolous insects, it employs a derived long germband mode of embryogenesis, more like that of Drosophila, whereas Tribolium undergoes an intermediate germband mode of embryogenesis, which is more similar to the ancestral mechanism. Comparing the embryonic development and genetic regulation of early patterning events in these three insects has given invaluable insights into insect evolution. The similar mode of embryogenesis of Drosophila and Nasonia is reflected in their reliance on maternal morphogenetic gradients. However, they employ different genes as maternal factors, reflecting the evolutionary distance separating them. Tribolium, on the other hand, relies heavily on self-regulatory mechanisms other than maternal cues, reflecting its sequential nature of segmentation and the need for reiterated patterning.
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Affiliation(s)
- Ezzat El-Sherif
- Program of Genetics, Kansas State University, Manhattan, Kansas
| | - Jeremy A Lynch
- Institute for Developmental Biology, University of Cologne, Cologne, Germany
| | - Susan J Brown
- Division of Biology, Kansas State University, Manhattan, Kansas
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93
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Garcia M, Stathopoulos A. Lateral gene expression in Drosophila early embryos is supported by Grainyhead-mediated activation and tiers of dorsally-localized repression. PLoS One 2011; 6:e29172. [PMID: 22216201 PMCID: PMC3245246 DOI: 10.1371/journal.pone.0029172] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Accepted: 11/22/2011] [Indexed: 12/20/2022] Open
Abstract
The general consensus in the field is that limiting amounts of the transcription factor Dorsal establish dorsal boundaries of genes expressed along the dorsal-ventral (DV) axis of early Drosophila embryos, while repressors establish ventral boundaries. Yet recent studies have provided evidence that repressors act to specify the dorsal boundary of intermediate neuroblasts defective (ind), a gene expressed in a stripe along the DV axis in lateral regions of the embryo. Here we show that a short 12 base pair sequence ("the A-box") present twice within the ind CRM is both necessary and sufficient to support transcriptional repression in dorsal regions of embryos. To identify binding factors, we conducted affinity chromatography using the A-box element and found a number of DNA-binding proteins and chromatin-associated factors using mass spectroscopy. Only Grainyhead (Grh), a CP2 transcription factor with a unique DNA-binding domain, was found to bind the A-box sequence. Our results suggest that Grh acts as an activator to support expression of ind, which was surprising as we identified this factor using an element that mediates dorsally-localized repression. Grh and Dorsal both contribute to ind transcriptional activation. However, another recent study found that the repressor Capicua (Cic) also binds to the A-box sequence. While Cic was not identified through our A-box affinity chromatography, utilization of the same site, the A-box, by both factors Grh (activator) and Cic (repressor) may also support a "switch-like" response that helps to sharpen the ind dorsal boundary. Furthermore, our results also demonstrate that TGF-β signaling acts to refine ind CRM expression in an A-box independent manner in dorsal-most regions, suggesting that tiers of repression act in dorsal regions of the embryo.
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Affiliation(s)
- Mayra Garcia
- Division of Biology, California Institute of Technology, Pasadena, California, United States of America
| | - Angelike Stathopoulos
- Division of Biology, California Institute of Technology, Pasadena, California, United States of America
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94
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Dolfini D, Gatta R, Mantovani R. NF-Y and the transcriptional activation of CCAAT promoters. Crit Rev Biochem Mol Biol 2011; 47:29-49. [PMID: 22050321 DOI: 10.3109/10409238.2011.628970] [Citation(s) in RCA: 171] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The CCAAT box promoter element and NF-Y, the transcription factor (TF) that binds to it, were among the first cis-elements and trans-acting factors identified; their interplay is required for transcriptional activation of a sizeable number of eukaryotic genes. NF-Y consists of three evolutionarily conserved subunits: a dimer of NF-YB and NF-YC which closely resembles a histone, and the "innovative" NF-YA. In this review, we will provide an update on the functional and biological features that make NF-Y a fundamental link between chromatin and transcription. The last 25 years have witnessed a spectacular increase in our knowledge of how genes are regulated: from the identification of cis-acting sequences in promoters and enhancers, and the biochemical characterization of the corresponding TFs, to the merging of chromatin studies with the investigation of enzymatic machines that regulate epigenetic states. Originally identified and studied in yeast and mammals, NF-Y - also termed CBF and CP1 - is composed of three subunits, NF-YA, NF-YB and NF-YC. The complex recognizes the CCAAT pentanucleotide and specific flanking nucleotides with high specificity (Dorn et al., 1997; Hatamochi et al., 1988; Hooft van Huijsduijnen et al, 1987; Kim & Sheffery, 1990). A compelling set of bioinformatics studies clarified that the NF-Y preferred binding site is one of the most frequent promoter elements (Suzuki et al., 2001, 2004; Elkon et al., 2003; Mariño-Ramírez et al., 2004; FitzGerald et al., 2004; Linhart et al., 2005; Zhu et al., 2005; Lee et al., 2007; Abnizova et al., 2007; Grskovic et al., 2007; Halperin et al., 2009; Häkkinen et al., 2011). The same consensus, as determined by mutagenesis and SELEX studies (Bi et al., 1997), was also retrieved in ChIP-on-chip analysis (Testa et al., 2005; Ceribelli et al., 2006; Ceribelli et al., 2008; Reed et al., 2008). Additional structural features of the CCAAT box - position, orientation, presence of multiple Transcriptional Start Sites - were previously reviewed (Dolfini et al., 2009) and will not be considered in detail here.
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Affiliation(s)
- Diletta Dolfini
- Dipartimento di Scienze Biomolecolari e Biotecnologie, Università degli Studi di Milano, Milan, Italy
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95
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Stevense M, Chubb JR, Muramoto T. Nuclear organization and transcriptional dynamics in Dictyostelium. Dev Growth Differ 2011; 53:576-86. [PMID: 21585360 DOI: 10.1111/j.1440-169x.2011.01271.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The Dictyostelium model has a set of features uniquely well-suited to developing our understanding of transcriptional control. The complete Dictyostelium discoideum genome sequence has revealed that many of the molecular components regulating transcription in larger eukaryotes are conserved in Dictyostelium, from transcription factors and chromatin components to the enzymes and signals that regulate them. In addition, the system permits visualization of single gene firing events in living cells, which provides a more detailed view of transcription and its relationships to cell and developmental processes. This review will bring together the available knowledge of the structure and dynamics of the Dictyostelium nucleus and discuss recent transcription imaging studies and their implications for stability and accuracy of cell decisions.
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Affiliation(s)
- Michelle Stevense
- Division of Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
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96
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Mrinal N, Tomar A, Nagaraju J. Role of sequence encoded κB DNA geometry in gene regulation by Dorsal. Nucleic Acids Res 2011; 39:9574-91. [PMID: 21890896 PMCID: PMC3239199 DOI: 10.1093/nar/gkr672] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Many proteins of the Rel family can act as both transcriptional activators and repressors. However, mechanism that discerns the ‘activator/repressor’ functions of Rel-proteins such as Dorsal (Drosophila homologue of mammalian NFκB) is not understood. Using genomic, biophysical and biochemical approaches, we demonstrate that the underlying principle of this functional specificity lies in the ‘sequence-encoded structure’ of the κB-DNA. We show that Dorsal-binding motifs exist in distinct activator and repressor conformations. Molecular dynamics of DNA-Dorsal complexes revealed that repressor κB-motifs typically have A-tract and flexible conformation that facilitates interaction with co-repressors. Deformable structure of repressor motifs, is due to changes in the hydrogen bonding in A:T pair in the ‘A-tract’ core. The sixth nucleotide in the nonameric κB-motif, ‘A’ (A6) in the repressor motifs and ‘T’ (T6) in the activator motifs, is critical to confer this functional specificity as A6 → T6 mutation transformed flexible repressor conformation into a rigid activator conformation. These results highlight that ‘sequence encoded κB DNA-geometry’ regulates gene expression by exerting allosteric effect on binding of Rel proteins which in turn regulates interaction with co-regulators. Further, we identified and characterized putative repressor motifs in Dl-target genes, which can potentially aid in functional annotation of Dorsal gene regulatory network.
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Affiliation(s)
- Nirotpal Mrinal
- Laboratory of Molecular Genetics, Centre for DNA Fingerprinting and Diagnostics, Nampally, Hyderabad 500001, India.
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97
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Mizutani CM, Bier E. EvoD/Vo: the origins of BMP signalling in the neuroectoderm. Nat Rev Genet 2011; 9:663-77. [PMID: 18679435 DOI: 10.1038/nrg2417] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The genetic systems controlling body axis formation trace back as far as the ancestor of diploblasts (corals, hydra, and jellyfish) and triploblasts (bilaterians). Comparative molecular studies, often referred to as evo-devo, provide powerful tools for elucidating the origins of mechanisms for establishing the dorsal-ventral and anterior-posterior axes in bilaterians and reveal differences in the evolutionary pressures acting upon tissue patterning. In this Review, we focus on the origins of nervous system patterning and discuss recent comparative genetic studies; these indicate the existence of an ancient molecular mechanism underlying nervous system organization that was probably already present in the bilaterian ancestor.
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Affiliation(s)
- Claudia Mieko Mizutani
- Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, 92093-0349, USA.
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98
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High resolution mapping of Twist to DNA in Drosophila embryos: Efficient functional analysis and evolutionary conservation. Genome Res 2011; 21:566-77. [PMID: 21383317 DOI: 10.1101/gr.104018.109] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cis-regulatory modules (CRMs) function by binding sequence specific transcription factors, but the relationship between in vivo physical binding and the regulatory capacity of factor-bound DNA elements remains uncertain. We investigate this relationship for the well-studied Twist factor in Drosophila melanogaster embryos by analyzing genome-wide factor occupancy and testing the functional significance of Twist occupied regions and motifs within regions. Twist ChIP-seq data efficiently identified previously studied Twist-dependent CRMs and robustly predicted new CRM activity in transgenesis, with newly identified Twist-occupied regions supporting diverse spatiotemporal patterns (>74% positive, n = 31). Some, but not all, candidate CRMs require Twist for proper expression in the embryo. The Twist motifs most favored in genome ChIP data (in vivo) differed from those most favored by Systematic Evolution of Ligands by EXponential enrichment (SELEX) (in vitro). Furthermore, the majority of ChIP-seq signals could be parsimoniously explained by a CABVTG motif located within 50 bp of the ChIP summit and, of these, CACATG was most prevalent. Mutagenesis experiments demonstrated that different Twist E-box motif types are not fully interchangeable, suggesting that the ChIP-derived consensus (CABVTG) includes sites having distinct regulatory outputs. Further analysis of position, frequency of occurrence, and sequence conservation revealed significant enrichment and conservation of CABVTG E-box motifs near Twist ChIP-seq signal summits, preferential conservation of ±150 bp surrounding Twist occupied summits, and enrichment of GA- and CA-repeat sequences near Twist occupied summits. Our results show that high resolution in vivo occupancy data can be used to drive efficient discovery and dissection of global and local cis-regulatory logic.
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99
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Bos JIB, Prince D, Pitino M, Maffei ME, Win J, Hogenhout SA. A functional genomics approach identifies candidate effectors from the aphid species Myzus persicae (green peach aphid). PLoS Genet 2010; 6:e1001216. [PMID: 21124944 PMCID: PMC2987835 DOI: 10.1371/journal.pgen.1001216] [Citation(s) in RCA: 309] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Accepted: 10/21/2010] [Indexed: 12/21/2022] Open
Abstract
Aphids are amongst the most devastating sap-feeding insects of plants. Like most plant parasites, aphids require intimate associations with their host plants to gain access to nutrients. Aphid feeding induces responses such as clogging of phloem sieve elements and callose formation, which are suppressed by unknown molecules, probably proteins, in aphid saliva. Therefore, it is likely that aphids, like plant pathogens, deliver proteins (effectors) inside their hosts to modulate host cell processes, suppress plant defenses, and promote infestation. We exploited publicly available aphid salivary gland expressed sequence tags (ESTs) to apply a functional genomics approach for identification of candidate effectors from Myzus persicae (green peach aphid), based on common features of plant pathogen effectors. A total of 48 effector candidates were identified, cloned, and subjected to transient overexpression in Nicotiana benthamiana to assay for elicitation of a phenotype, suppression of the Pathogen-Associated Molecular Pattern (PAMP)-mediated oxidative burst, and effects on aphid reproductive performance. We identified one candidate effector, Mp10, which specifically induced chlorosis and local cell death in N. benthamiana and conferred avirulence to recombinant Potato virus X (PVX) expressing Mp10, PVX-Mp10, in N. tabacum, indicating that this protein may trigger plant defenses. The ubiquitin-ligase associated protein SGT1 was required for the Mp10-mediated chlorosis response in N. benthamiana. Mp10 also suppressed the oxidative burst induced by flg22, but not by chitin. Aphid fecundity assays revealed that in planta overexpression of Mp10 and Mp42 reduced aphid fecundity, whereas another effector candidate, MpC002, enhanced aphid fecundity. Thus, these results suggest that, although Mp10 suppresses flg22-triggered immunity, it triggers a defense response, resulting in an overall decrease in aphid performance in the fecundity assays. Overall, we identified aphid salivary proteins that share features with plant pathogen effectors and therefore may function as aphid effectors by perturbing host cellular processes.
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Affiliation(s)
- Jorunn I. B. Bos
- Department of Disease and Stress Biology, The John Innes Centre, Norwich, United Kingdom
| | - David Prince
- Department of Disease and Stress Biology, The John Innes Centre, Norwich, United Kingdom
| | - Marco Pitino
- Department of Disease and Stress Biology, The John Innes Centre, Norwich, United Kingdom
| | - Massimo E. Maffei
- Plant Physiology Unit, Department of Plant Biology and Centre of Excellence CEBIOVEM, University of Turin, Turin, Italy
| | - Joe Win
- The Sainsbury Laboratory, Norwich, United Kingdom
| | - Saskia A. Hogenhout
- Department of Disease and Stress Biology, The John Innes Centre, Norwich, United Kingdom
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100
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Chromosomal organization at the level of gene complexes. Cell Mol Life Sci 2010; 68:977-90. [PMID: 21080026 PMCID: PMC3043239 DOI: 10.1007/s00018-010-0585-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Revised: 10/17/2010] [Accepted: 10/26/2010] [Indexed: 01/10/2023]
Abstract
Metazoan genomes primarily consist of non-coding DNA in comparison to coding regions. Non-coding fraction of the genome contains cis-regulatory elements, which ensure that the genetic code is read properly at the right time and space during development. Regulatory elements and their target genes define functional landscapes within the genome, and some developmentally important genes evolve by keeping the genes involved in specification of common organs/tissues in clusters and are termed gene complex. The clustering of genes involved in a common function may help in robust spatio-temporal gene expression. Gene complexes are often found to be evolutionarily conserved, and the classic example is the hox complex. The evolutionary constraints seen among gene complexes provide an ideal model system to understand cis and trans-regulation of gene function. This review will discuss the various characteristics of gene regulatory modules found within gene complexes and how they can be characterized.
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